Q&A Forum
Just installed YourDyno onto my old roller dyno. I think I am getting alot of noise in my rpm signal. I am using the hall sensor from yourdyno.com. I have installed the sensor directly on a roller with 80 teeth timing pulley, and also tried it on the brake with a 26 tooth timing gear. The results seem the same. When running steady state, say 25mph, I can see the rpm jumping occasionally, and the torque gauge reflecting the false increase in rpm.
Ive included a picture of 3 variations of the same run with different "graph filtering" The "RPM filter" is at 5 for all of these. For a test I set "rpm filter" to 8 and it helps quite a bit... but that is a bandaid and may cause me to miss anomalies in my tune.
Ive also included a raw log file.
Any ideas on whats going on? Is there something I am missing? Are they typically noisy? Should I put a scope on the sensor and see if the noise is real?
Hi,
Two things to do:
1) Check dimensions of the timing wheel against the spec at https://yourdyno.com/YourDynoHelp/brake-rpm-sensors/
2) Add a 1k pullup resistor between rpm signal and 5v at the connector. Sometimes that is necessary especially for long cables or high teeth count setups.
The rpm signal shall be clean.
Hi,
Two things to do:
1) Check dimensions of the timing wheel against the spec at https://yourdyno.com/YourDynoHelp/brake-rpm-sensors/
2) Add a 1k pullup resistor between rpm signal and 5v at the connector. Sometimes that is necessary especially for long cables or high teeth count setups.
The rpm signal shall be clean.
Thanks for the tips. I confirmed the trigger wheel is to spec and the air gap is in spec. I disconnected some noisy electrical equipment in my cabinet thinking it was causing noise but no luck.
Then I added the 1k pullup resistor, and its perfect!
Blue plot is before, black is after. Dyno is working great now!!!! Thats with graph filter very low and rpm filter at 0 😀